3,573 research outputs found

    Use of soil moisture information in yield models

    Get PDF
    There are no author-identified significant results in this report

    Clarification of the Bootstrap Percolation Paradox

    Full text link
    We study the onset of the bootstrap percolation transition as a model of generalized dynamical arrest. We develop a new importance-sampling procedure in simulation, based on rare events around "holes", that enables us to access bootstrap lengths beyond those previously studied. By framing a new theory in terms of paths or processes that lead to emptying of the lattice we are able to develop systematic corrections to the existing theory, and compare them to simulations. Thereby, for the first time in the literature, it is possible to obtain credible comparisons between theory and simulation in the accessible density range.Comment: 4 pages with 3 figure

    Evaluating the effectiveness of a sodium butyrate feed additive for the control of Salmonella carriage in finishing pigs

    Get PDF
    This study aimed to investigate the effectiveness of commercially available sodium butyrate to control the shedding of Salmonella on two Irish pig farms with a history of high Salmonella seroprevalence. On both farms, pens (12-17 pigs/pen) were randomly assigned to a control (finisher feed without additives) or an acid treatment (the same feed supplemented with 0.03% sodium butyrate) for 24-26 days prior to slaughter. On Farm A, Salmonella shedding was reduced in the acid group compared to the control group at the end of the treatment period (30% vs. 57% probability of detecting Salmonella in faeces, respectively; p\u3c0.05). However no effect of treatment was observed on Farm B, which could perhaps be explained by a concomitant infection by Lawsonia intracellularis. No significant differences in Salmonella recovery rates were observed from caecal digesta or ileocaecal/mesenteric lymph nodes collected at slaughter in either of the trials. Furthermore, feed intake, weight gain and feed conversion efficiency did not differ significantly between control and treatment groups on either farm

    Nonstomatal limitations are responsible for drought-induced photosynthetic inhibition in four C4 grasses

    Get PDF
    Here, the contribution of stomatal and nonstomatal factors to photosynthetic inhibition under water stress in four tropical C(4) grasses was investigated (Panicum coloratum, Bothriochloa bladhii, Cenchrus ciliaris and Astrebla lappacea ). Plants were grown in well watered soil, and then the effects of soil drying were measured on leaf gas exchange, chlorophyll a fluorescence and water relations. During the drying cycle, leaf water potential (Psi(leaf)) and relative water content (RWC) decreased from c. -0.4 to -2.8 MPa and 100-40%, respectively. The CO(2) assimilation rates (A) and quantum yield of PSII (Phi(PSII)) of all four grasses decreased rapidly with declining RWC. High CO(2) concentration (2500 mul l(-1)) had no effect on A or Phi(PSII) at any stage of the drying cycle. Electron transport capacity and dark respiration rates were unaltered by drought. The CO(2) compensation concentrations of P. coloratum and C. ciliaris rose sharply when leaf RWC fell below 70%. In P. coloratum, 5% CO(2) did not prevent the decline of O(2) evolution rates under water stress. We conclude that inhibition of photosynthesis in the four C(4) grasses under water stress is dependent mainly on biochemical limitations

    Muscle-directed gene therapy corrects Pompe disease and uncovers species-specific GAA immunogenicity

    Get PDF
    Pompe disease is a severe disorder caused by loss of acid α-glucosidase (GAA), leading to glycogen accumulation in tissues and neuromuscular and cardiac dysfunction. Enzyme replacement therapy is the only available treatment. AT845 is an adeno-associated viral vector designed to express human GAA specifically in skeletal muscle and heart. Systemic administration of AT845 in Gaa−/− mice led to a dose-dependent increase in GAA activity, glycogen clearance in muscles and heart, and functional improvement. AT845 was tolerated in cynomolgus macaques at low doses, while high doses caused anti-GAA immune response, inflammation, and cardiac abnormalities resulting in unscheduled euthanasia of two animals. Conversely, a vector expressing the macaque GAA caused no detectable pathology, indicating that the toxicity observed with AT845 was an anti-GAA xenogeneic immune response. Western blot analysis showed abnormal processing of human GAA in cynomolgus muscle, adding to the species-specific effects of enzyme expression. Overall, these studies show that AAV-mediated GAA delivery to muscle is efficacious in Gaa−/− mice and highlight limitations in predicting the toxicity of AAV vectors encoding human proteins in non-human species

    Coming Full Circle: Reflections and Inspirations from a Cystic Fibrosis Patient Scientist Panel

    Get PDF
    Care for many progressive chronic diseases continues to improve, allowing patients to survive and thrive for longer periods of time1. People living with such conditions may now find themselves able to achieve long-term goals in education and career development2. Many people now occupy the dual roles of scientist and patient3. This commentary article synthesizes experiences of scientists and advocates with the progressive genetic disease cystic fibrosis (CF) who collaborated on a career development session for the Cystic Fibrosis Foundation’s inaugural ResearchCon event in 2019. It explores how such collaborations affirm and transform individual perspectives on patient science and its importance in broader scientific research agenda setting. We first share our own individual insights about the experience and impact of the ResearchCon panel session before progressing to discussion and future directions centering the shared insights from one another’s reflections

    Metabolomics analysis in adults with High Bone Mass identifies a relationship between bone resorption and circulating citrate which replicates in the general population

    Get PDF
    Objective: Bone turnover, which regulates bone mass, may exert metabolic consequences, particularly on markers of glucose metabolism and adiposity. To better understand these relationships, we examined cross-sectional associations between bone turnover markers (BTMs) and metabolic traits in a population with high bone mass (HBM, BMD Z-score>+3.2). Design: β-C-terminal telopeptide of type-I collagen (β-CTX), procollagen type-1 amino-terminal propeptide (P1NP) and osteocalcin were assessed by electrochemiluminescence immunoassays. Metabolic traits, including lipids and glycolysis-related metabolites, were measured using Nuclear Magnetic Resonance spectroscopy. Associations of BTMs with metabolic traits were assessed using Generalized Estimating Equation linear regression, accounting for within-family correlation, adjusting for potential confounders (age, sex, height, weight, menopause, bisphosphonate and oral glucocorticoid use). Results: 198 adults with HBM had complete data, mean [SD] age 61.6 [13.7] years; 77% female. Of 23 summary metabolic traits, citrate was positively related to all BTMs: adjusted ββ-CTX=0.050 (95% CI 0.024,0.076),p=1.71x10-4, βosteocalcin=6.54x10-4 (1.87x10-4,0.001),p=0.006 and βP1NP=2.40x10-4 (6.49x10-5,4.14x10-4),p=0.007 (β= increase in citrate (mmol/L) per 1Οg/L BTM increase). Inverse relationships of β-CTX (β=-0.276 -0.434,-0.118],p=6.03x10-4) and osteocalcin (-0.004 [-0.007,-0.001],p=0.020) with triglycerides were also identified. We explored the generalizability of these associations in 3,664 perimenopausal women (age 47.9 [4.4] years) from a UK family cohort. We confirmed a positive, albeit lower magnitude, association between β-CTX and citrate (adjusted βwomen=0.020 [0.013,0.026],p=1.95x10-9) and an inverse association of similar magnitude between β-CTX and triglycerides (β=-0.354 [-0.471,-0.237],p=3.03x10-9). Conclusions: Bone resorption is positively related to circulating citrate and inversely related to triglycerides. Further studies are justified to determine whether plasma citrate or triglyceride concentrations are altered by factors known to modulate bone resorption, such as bisphosphonates
    • …
    corecore